Subject: [bug#78373] [PATCH] gnu: mosquitto: Update to 2.0.21.

From: Evgeny Pisemsky <[email-masked]>
Date: Fri, 16 May 2025 14:30:58 +0300

At first I wanted to enable websockets support, but guix lint displayed lots of CVEs on the current version of mosquitto, so this update is desirable.

Or I can prepare and send here a series of patches to make everything at once to avoid multiple rebuilds.